Colour with Copper

We used the following glass and inclusions in the examples below:

Examples of copper included in glass:

Below are tiles made in our studio using copper foil or copper oxide and different glass styles. In each case the base glass is the layer directly on the kiln shelf, then the copper is added on top of the base glass, this is then topped with the cap glass before firing to a full fuse. Click on an image to enlarge it:

Tips on keeping copper inclusions red: 

Sometimes when using copper wire, foil or other inclusions, the copper will turn a dark blue on firing rather than the expected red. This is caused by the metal oxidising during firing, which happens where the copper is exposed to air. To minimise the amount of air that the copper is exposed to during the firing you can:

• Keep copper inclusions away from the edges of your design.
• Try not to use any glue which will burn and cause oxidation.
• Keep the inclusions to a minimum to try to trap as little air as possible.
• Avoid using copper oxide as this will make copper foil turn blue.
• Where possible, scrub the copper with some wire wool and clean it before you fuse it to remove any tarnishing.
• Want to keep the copper colour? Boric acid and warm water painted onto the copper will keep it copper coloured but it is difficult to control.